Posted
by
Soulskillon Friday August 31, 2012 @01:01PM
from the everything-in-moderation dept.

Hugh Pickens writes "Thanks to fast-paced television crime shows such as CSI, we have come to regard DNA evidence as incontestable. But BBC reports that David Butler has every right to be cynical about the use of DNA evidence by the police. Butler spent eight months in prison, on remand, facing murder charges after his DNA was allegedly found on the victim. 'I think in the current climate [DNA] has made police lazy,' says Butler. 'It doesn't matter how many times someone like me writes to them, imploring they look at the evidence... they put every hope they had in the DNA result.' The police had accused Butler of murdering a woman, Anne Marie Foy, in 2005 — his DNA sample was on record after he had willingly given it to them as part of an investigation into a burglary at his mother's home some years earlier. But Butler has a rare skin condition, which means he sheds flakes of skin, leaving behind much larger traces of DNA than the average person. Butler worked as a taxi driver, and so it was possible for his DNA to be transferred from his taxi via money or another person, onto the murder victim. The case eventually went to trial and Butler was acquitted after CCTV evidence allegedly placing Butler in the area where the murder took place was disproved. Professor Allan Jamieson, head of the Glasgow-based Forensic Institute, has become a familiar thorn in the side of prosecutors seeking to rely on DNA evidence and has appeared as an expert witness for the defense in several important DNA-centered trials, most notably that of Sean Hoey, who was cleared of carrying out the 1998 Omagh bombing, which killed 29 people. Jamieson's main concern about the growing use of DNA in court cases is that a number of important factors — human error, contamination, simple accident — can suggest guilt where there is none. 'Does anyone realize how easy it is to leave a couple of cells of your DNA somewhere?' says Jamieson. 'You could shake my hand and I could put that hand down hundreds of miles away and leave your cells behind. In many cases, the question is not "Is it my DNA?", but 'How did it get there?"'"

this is england but here in the US you need beyond a reasonable doubt. the cops can check the phone for prints and there is a record of movement by tracking every tower it hits. combine with CCTV evidence of stores and other cameras along with credit card transactions it should be fairly easy to show where you were

i've been on a criminal case jury and we ruled not guilty in a half hour because the cops had a weak case

I know the standard of proof is "beyond a reasonable doubt" here, but what I raised is a reasonable doubt. It's the owner's phone, so obviously it would have prints all over it. That doesn't really help. And it's trivial for any criminal with half a brain to simply leave their phone at home, so it's extremely reasonable to doubt the phone's location as proof of the owner's location.

The phone can be used as corroborating evidence to back up evidence that already shows the person was at home (or wherever), but it's useless by itself. And if you have the other evidence, you hardly need to know where the phone was. So in either case, the phone's location is kind of a moot point.

The "reasonable doubt" standard of proof applies only to the prosecution. The defence does not have to prove anything, either beyond reasonable doubt or to any standard of proof whatsoever. They merely have to raise enough evidence to prevent the prosecution from proving their case beyond reasonable doubt.That being the case it's meaningless to talk about whether there is reasonable doubt as to whether the phone was in the owner's possession. That is simply never a relevant question. The question is whether, taking the case in its totality, the evidence is such that a jury could be satisfied beyond reasonable doubt that the defendant is guilty. If the evidence amounted to an inconclusive DNA match and phone records that did not place his phone at the place of the murder then the evidence would certainly not be sufficient. That is the case notwithstanding that none of the evidence is directly exculpatory.(I'm not saying that that was the totality of the evidence in this case; in fact, given that he was denied bail for 8 months, I suspect that there was both more evidence and some history of criminality. That is simply speculation however.)

You're just playing with semantics. If you mentally rewrite what I said to be about how the cell phone does not raise a reasonable doubt, my point doesn't change at all. It's evidence that cannot be relied upon except in the presence of other evidence, and the presence of that other evidence would render the cell phone evidence needless.

You're just playing with semantics. If you mentally rewrite what I said to be about how the cell phone does not raise a reasonable doubt, my point doesn't change at all.

But the phone indicating that the person was at his house does raise a "reasonable doubt" unless there is other evidence that proves he was somewhere else - not that his DNA was there but him. If they give a provide a reasonable explanation for how the DNA go there and have proof that his phone was somewhere else it all adds to a reasonable doubt.

But in that case, the reasonable explanation is all that is needed. The cell phone can't stand on its own, it needs something to back it up. And if you have the something to back it up, you don't need the cell phone evidence too. So the phone is either not enough, or superfluous.

The defense does not have to prove anything. They only need to instill reasonable doubt. The cell phone location by itself does instill doubt - I'll concede that the amount of doubt depends on the other evidence. But if there is just one, reasonably believable, alternate version of events that does not incriminate the defendant, and is not disproved by the evidence, no matter how unlikely, the jury must return a verdict of not guilty.

The cell phone location, by itself, instills no doubt whatsoever in my mind because it proves nothing by itself. As I keep saying, only other evidence can instill that doubt. And your statement of "no matter how unlikely" is untrue. That's why the standard is "beyond a reasonable doubt", not "beyond any doubt".

If one starts from a blank slate, the defense has to prove nothing. But assuming that sufficiently good evidence has been presented by the prosecution, the burden is back on the defense. If they can't

If they can't provide something which refutes the prosecution's case, then they have failed to instill doubt, and the cell phone isn't close to what is needed for that.

The defense doesn't have to "provide" anything, and certainly doesn't have to "refute" anything, as the definition of refute [merriam-webster.com] is:

1: to prove wrong by argument or evidence : show to be false or erroneous

The very act of refutation is "proving wrong." You cannot refute unless you prove, and there is no, repeat no burden of proof on the defense. The defense does not have to prove the prosecution wrong, or show that any of their evidence or facts are incorrect. The defense can cede every fact and piece of evidence the prosecution can provide but simply raise enough doubt that this evidence is sufficient to reasonably prove their case. The defense can be successful simply telling another tale with the same evidence.

For instance, the police arrive on the scene to find bigstrat2003 and zzsmirkzz locked in room with a dead prostitute. A knife is buried in the back of the prostitute's neck. Both people are wearing gloves, neither has blood spatter on them, and neither of them are talking. The prosecution claims "bigstrat2003 did it! He was in the room, he had the opportunity, and bigstrat2003 bought the knife earlier that day!" You don't have to prove you weren't in the room. Don't have to prove you didn't buy the knife. You can cede you had the opportunity. You don't have to even say "I didn't do it." All the defense has to say is, "Isn't it possible bigstrat2003 gave the knife to zzsmirkzz, and zzsmirkzz killed him?" Done, reasonable doubt established, and bigstrat2003 walks. No "refutation" required.

Does that make sense now? You don't have to prove or refute anything to establish "reasonable doubt." Just tell another story with the same facts that could be "reasonably" true. However, the more evidence the prosecution has, and the stronger that evidence is, the harder it becomes to tell another story that fits the facts and is still reasonable. If 30 million people watched you murder someone on live TV while it was recorded from 15 different camera angles, and police apprehended you immediately, you could cede all those facts and claim it was not, in fact you, but a doppleganger from an alternate dimension who switched places back with you immediately after committing the crime, but that would hardly be "reasonable."

Technically the defense doesn't need to "prove" anything, but after all is said and done, your chances boil down the opinion of 12 of your "peers" sitting in the jury chair.

The goal of the prosecution is not so much to "prove" the case in a mathematical sense, though that does tend to help the case, but rather to convince the 12 members of the jury that you are guilty. There are a whole list of logical fallacies [wikipedia.org] that might just convince a jury uneducated in formal logic, its a reasonable assumption to make.

The cell phone location, by itself, instills no doubt whatsoever in my mind because it proves nothing by itself.

As a single juror okay this might not instill any doubt for you but you can't speak for the other 11.

And your statement of "no matter how unlikely" is untrue. That's why the standard is "beyond a reasonable doubt"

I said at the beginning of my statement that "if there is just one, reasonably believable, alternate version..." so I already covered that the doubt is "Reasonable". A version of events can be unlikely and still be reasonably supported by the evidence the two are not mutually exclusive.

>>>it's trivial for any criminal with half a brain to simply leave their phone at home, so it's extremely reasonable to doubt the phone's location as proof of the owner's location.

You are right but I would weigh the evidence that shows His phone was at home, versus the evidence that they found a piece of skin in a woman's wallet, stuck to some money. I am aware of the fact that money travels between a lot of hands, especially for the defendent who is a taxi driver, so his DNA on a piece of money d

The police will try to send any kind of weak shit that they can to the district attorney, because they can then mark the case solved and blame the DA or the Grand Jury should they fail to indict. The police commanders are happy because they get the closed case stats, the prosecutors stay happy because they don't take weak shit cases to trial, so their conviction rate stays up.

Everyone else loses. The whole world shines shit and declares it to be gold.

Also, this doesn't sound like a failure of DNA, this sounds like a failure of the detectives to properly interpret trace evidence.

Actually that's not the cell company tracking your phone, that's your phone "reporting in" to the towers. What the guy above you is talking about is whether or not the cell company keeps this information for even a second after your phone has reported in from a NEW tower. Most phone companies keep records just because they can pretty much... But in some places where that is legal some companies are still conscious enough of the privacy of their users that they don't actually track the PAST positions of thei

Thanks to fast-paced television crime shows such as CSI: Crime Scene Investigation, we have come to regard DNA evidence as uncontestable.

Why is an unrealistic American television show being referenced about a case in Liverpool by a UK news source? Is horrible American television that prevalent? I'm not seeing The Mighty Boosh referenced in The New York Times in regards to the legalization of marijuana. And who cares if a television show makes the public think DNA evidence is incontestable? That xenophobic vapid televisions series 24 appears to be proof positive justification for torture and Judge Dread style murder but that should not alter the way our courts rule.

The prosecution in Liverpool Crown Court has no other proof that ties Butler to the murder — showing just how much store they place in the science.

Okay, congratulations, that has to be the most jaw dropping thing I've read in quite sometime about justice in the UK. Are you serious? DNA should be used as one piece of a very large puzzle used to prove beyond a reasonable doubt that this person was present at some point in time. It is a flawed process and should be used as one piece of many pieces of evidence against someone. If you put that much weight on it, framing someone just became a one step process. Hopefully it will improve but just as hopefully it will always remain as one supporting piece of evidence requiring many other avenues of evidence before a conviction.

Plus, if they had any idea as to how science works, they would know that one datum doesn't constitute reliable evidence at all. Even finding the same DNA in multiple locations doesn't rule out systematic contamination. Multiple types of evidence are needed to confirm causation with anything. It scares me that people's entire lives can depend on methods that would get any scientist laughed out of the room.

"It scares me that people's entire lives can depend on methods that would get any scientist laughed out of the room."

I have been saying this for years. It is ridiculously easy to contaminate or even plant DNA. Fingerprints are relatively hard to fake, and they don't "accidentally" move from place to place. However, DNA does accidentally move from place to place. Worse: drop a few skin scrapings or spit from someone in the right places, and watch the police foam at the mouth in rabid excitement.

It's worse than ridiculous. It's a tragedy that doesn't need to exist.

Indeed, and it's not exactly hard for someone to do the opposite and significantly reduce their own dna output if they were trying to frame someone. The semiconductor industry has been improving techniques to keep the rate of human contamination from technicians/researchers down in their clean rooms for decades, and a couple orders of magnitude difference is considered basic.

Only our lowest courts use juries. Panels of experts (multiple judges) has generally worked quite well in higher courts. Stuff like

The problem is they get away with it. Look at Barry George, convicted based on flawed forensic evidence consisting of a single spec of gunpowder that might not actually have been gunpowder or even from his clothes. Sometimes, as in that case, the truth comes to light and the error is corrected, but often it doesn't.

There is no sanction against the police or the forensic services or expert witnesses for these mistakes or outright fabrications. Under pressure to deliver results and apparently unwilling to pro

I really dislike CSI for a long list of reasons, but I'll give the writers some credit here - at least the "omg we have the DNA's" is usually a setup for an interview (interrogation) where they use it as pressure and the murderer gives up everything when they realize they're caught. It's how they wrap up the crime story bit. There's also usually another element there, like "that gas station happened to have Las Vegas style, super high-res security cameras with $1,000 lenses, and you posed for them". You know, something to make it look like they're more than just semen collectors.

The silly thing really... Crime scene analysts are just the forensics people. They shouldn't even be interviewing witnesses, or doing any non-forensics investigation at all. They aren't trained for it. They do the forensics, write the report, and the report goes off to the detectives.

It's kinda sad really. It's just fiction and certainly they exaggerate the prevalence of DNA (for one thing, the near instant analysis), but they still generally insist on having a stronger case against the defendant than the real police do. Especially the way they also willingly look at exculpatory evidence rather than trying to shove it under the rug where the defense won't find it.

DNA should be used as one piece of a very large puzzle used to prove beyond a reasonable doubt that this person was present at some point in time

Within some error margin, and that error margin is quite a bit higher than you might expect. If you do not exclude identical twins, even if there were no laboratory errors at all, the probability of finding two people with the same DNA profile would be 1 in 1000; when laboratory errors are included in the analysis, that probability can become high enough to pass the threshold of "reasonable doubt."

Even if we assume no lab errors, no identical twins, and no measurement errors, DNA evidence is still not sufficient. I could plant someone's DNA at a crime scene without too much difficulty (consider how many personal items in your bathroom will have testable DNA on them -- a razor, a toothbrush, a comb). There have been cases of criminals finding ways to substitute another person's DNA for their own, including one case of a doctor who actually managed to hide another person's blood in one of his veins, thus faking his innocence.

One data point is not enough to draw any sort of conclusion; it might point you in the right direction, but nothing more.

There have been cases of criminals finding ways to substitute another person's DNA for their own, including one case of a doctor who actually managed to hide another person's blood in one of his veins, thus faking his innocence.

Here. [wikipedia.org] He surgically implanted a vial of someone else's blood into his arm prior to taking the DNA test. He manipulated the collector to take it from his arm rather than the standard finger prick.

Which is why drug tests for athletes are incredibly intrusive: someone is watching them pee. I I don't mean watching them sit on the loo or turn their back, no, they have to stand one meter or so away and watch the graphic details the whole time. Because there's been several stories of cyclists putting a condom with somebody else's urine in their ass (!!!) and using a tube to get it out at the right time. No shit, drugs will make you do the crasiest shit.

Why is an unrealistic American television show being referenced about a case in Liverpool by a UK news source? Is horrible American television that prevalent?

Because you're being an intentionally obtuse pedant. First of all, the statement said 'shows like CSI' and if you think international crime shows don't use DNA evidence the same way you're quite naive. The specific show wasn't the point and the reason this is a problem is that popular culture shows has inflated DNA evidence as being some 100% accurate measure of guilt such that juries now will demand DNA evidence in order to even fathom the idea that the persn was guilty. Also, theynare easily misled by DNA evodence in wrongfully convicting people since they don't understand the probabilities or other curcumstances involved that could lead to the DNA being at the crime scene. Hell, The Independent in the UK wrote an article about juries being misled by DNA evidence back in 1994.

Also, yes, CSI has aired internationally for many years with the U.K. being one of those places. Many American shows air internationally. That this is somehow news to you is hilarious.

Okay, from watching crime shows, I've seen a plenty of episodes where DNA evidence is left by a person who turns out to not be the killer. These shows like to play fast and loose with forensic technology, but if the crime could be solved instantly using some magical technology like DNA how would the script writers fill up a 40 minute show? In fact one episode of Lie To Me centered around the main character leaving DNA on the victim. Are people really getting that DNA evidence proves guilt from TV shows?

There have been a number of episodes where they show DNA evidence as fallible. I recall one episode where the suspect was a chimera ( two eggs fertilized by two separate sperm that normally would have developed into fraternal twins, but somehow they merged into a single embryo, and thus into a single person). The suspect knew he had two sets of DNA, and used that knowledge to spoof the tests.

There was another episode where they had searched for fingerprints on a matchbook (using a dye that would attach

No, no one is blaming Americans. CSI is just a convenient example considering it's the most watched show internationally. Stop being such a pedant about that specific sentence. They could have said 'Shows like Midsomer Murders' but do you think more or less people would have heard of that versus CSI? Even people who don't watch CSI can tell tou what it is whereas the other would get you mostly blank stares.

So what you're saying is that all modern crime drama use DNA evidence... but when those dramas are negatively influencing rational thought, it's those stupid Americans and their television that are causing Liverpudlian court cases to go awry. Yep, those Yanks sure are thick. And we are, but it does get tiresome when everything is our fault.

Dude, chill:) I'm a Yank too, but I didn't get that out of TFS* or anyone else's posts here. There is a difference between what is implied, and what is inferred. I think you have *inferred* far more than the author intended.

* in true/. tradition, I didn't RTFA, so if TFA more explicitly blames Americans, then I respectfully withdraw my comment.

Why is an unrealistic American television show being referenced about a case in Liverpool by a UK news source?

American TV shows are hugely popular in the UK. British shows don't travel across the Atlantic so well, so their comedy often has to be translated into an American version where the jokes are spelled out more explicitly to fit with American humour. Hence American versions of British shows strike the British audience as not being funny.

I digress.

I agree that CSI is unrealistic. I watched it once and thought it was badly written and badly acted sci-fi. They show technology that clearly does not exist. Their

Eyewitness accounts are yes, traditional, and about just as bad/good as DNA is. They can't stand on their own. Eyewitnesses routinely lie, and not necessarily because they intend to, but because people are horrible at accurate recall. We imagine we're much better than we really are. Think about it like this: you supposedly remember down to the last detail what happened at some time and place. Yet, how easy it is for most of us to learn at school? Do you read a book once and go to the exam with total recall

British shows don't travel across the Atlantic so well, so their comedy often has to be translated into an American version where the jokes are spelled out more explicitly to fit with American humour.

You sound like an American tv producer, not an American. Me and most of my friends prefer Britcoms to Sitcoms; example, the Office. British version far superior in every way. So stick your "American humour" up you know where.

British shows don't travel across the Atlantic so well, so their comedy often has to be translated into an American version where the jokes are spelled out more explicitly to fit with American humour.

You sound like an American tv producer, not an American. Me and most of my friends prefer Britcoms to Sitcoms; example, the Office. British version far superior in every way. So stick your "American humour" up you know where.

Er, I'm not an American. I'm not British either. What has my nationality got to do with the price of fish anyway? I don't care what you and your intimate circle of friends think. I'm well aware that there is a certain market for Brit TV in America, I didn't say there wasn't. I simply said that if a British TV show wants to make it big in America then it has to get translated into the more explicit American humour.

Why is an unrealistic American television show being referenced about a case in Liverpool by a UK news source?...It is a flawed process and should be used as one piece of many pieces of evidence against someone. If you put that much weight on it, framing someone just became a one step process. Hopefully it will improve but just as hopefully it will always remain as one supporting piece of evidence requiring many other avenues of evidence before a conviction.

I think you answered your own question there. What I got from TFS was that despite the fact that DNA evidence "...is a flawed process..." the public's perception (which is due, in no small part, to television shows like CSI) is that it is infallible evidence. "Oh, you're DNA was present on the victim? Done deal, you're guilty."

Unfortunately, AFAIK, DNA evidence isn't a digital (i.e., yes or no) proposition, it's a matter of probability: the answer is "there is a xx% chance th

Why is an unrealistic American television show being referenced about a case in Liverpool by a UK news source?

Bacause most jurors do watch TV, that you don't is irrelevant. CSI is the defining show of that genre - you may notice the phrase "show such as CSI" was used not only CSI. Even jurors who don't watch such TV shows likely read a newspaper or watch news written by people who have watched said shows and that portray DNA evidence as a slam-dunk.

I guess I'm wondering why they are down on DNA matching, when it did exactly what it's supposed to. This was a failure to either interpret the results of the test, as you suggest; or a failure to interpret the trace evidence that called for the DNA match to begin with.

Okay, congratulations, that has to be the most jaw dropping thing I've read in quite sometime about justice in the UK. Are you serious? DNA should be used as one piece of a very large puzzle used to prove beyond a reasonable doubt that this person was present at some point in time.

Yep. DNA is supposed to be used to check if an existing suspect was at the scene of the crime. In that case it's a very good indicator. If however, you take some DNA from the scene and compare it to everyone in a database you'll

And CSI does? Here's a proposed sentence for you: "Modern television like The Mighty Boosh has a lot of people thinking that smoking marijuana is spiritual, fun, cool and without any repercussion." It doesn't have to be factual for a news source to cite it as evidence of its influence on public perception.

By "it" I mean TMB, though if the cap fits...

Wow, I bet The New York Times is just seething after that burn. I'll get Will Shortz on the phone right now and see if he can write crosswords for a more reputable news source like The New York Post. I

Clearly you only think in simple yes/no black/with terms, but differences of degree can be significant. CSI shows live actors, the characters are humans rather than supernatural entities or space aliens, they do a job we've heard of and it's set in a real city. The other has a guy jamming with the drummer from Santana when a door opens in his head which enable him to defeat a monster made of video tape.

Prosecutors themselves tend to be at fault for this, too. They will eiteher highly downplay the probabilities part or will outright not mention that DNA matching is not exact. Pop culture is surely a big part of the claim but its abuse by police and prosecutors should not be understated.

It is not like DNA matching is as exact as solving a math problem. There is experimental error, and the error rates are sufficiently high that DNA evidence should never be considered enough to convict someone; DNA evidence with additional supporting evidence should be the minimum standard.

That is what is so terrifying about the police having DNA samples on hand apriori: NO MORE UNSOLVED CASES!! Contaminate the evidence with someone's DNA you already have on hand (if you don't like them for racial, political, or personal reasons, that's just gravy), and bingo! Instant conviction by idiot juries who can't spell GUILTY without using the letters D, N, and A.

That is what is so terrifying about the police having DNA samples on hand apriori: NO MORE UNSOLVED CASES!! Contaminate the evidence with someone's DNA you already have on hand (if you don't like them for racial, political, or personal reasons, that's just gravy), and bingo! Instant conviction by idiot juries who can't spell GUILTY without using the letters D, N, and A.

Also, isn't casting doubt on DNA based evidence also a double edged sword? You've got groups like the Innocence Project that rely almost entirely on DNA as a means of proving their client's innocence. If you can cast doubt on DNA evidence when trying to convict someone, you can also cast doubt on that evidence when trying to prove someone innocent.

Not really. The perfect DNA test returns a result of a comparison between Sample A, and Sample B. The results are either 'MATCH, NO MATCH, or inconclusive'.

The problem is that people are basically adding meta-data to the Yes/No/error results. A confirmation a match is nothing more than a confirmation of a match, it doesn't tell you a single thing more than that. It doesn't even tell you that the person producing that DNA was there. Additional evidence is necessary in order to draw that conclusion.

However, this is NOT a problem with the traditional exculpatory DNA evidence. The casting of doubt is on the meta-results of the DNA, not the match/mismatch itself.

Thus, with exculpatory DNA evidence, the defence isn't trying to prove that the Defendant was in any particular location, all they are trying to prove is that DNA sample A does/doesn't match DNA sample B.

If you have a DNA sample from a crime scene, and I'm trying to show that such a sample does not match my client, it doesn't matter if my client was in the room, out of the room, or 3,000 miles away. If the DNA doesn't match, then the DNA doesn't match. I'm not trying to prove anything more than that.

It is the prosecution that is trying to add that extra data to the DNA, not the defense. The prosecutor has to first show that the DNA matches, THEN the prosecutor must also present evidence that the DNA could only be where it was because the defendant put it there.

Again, the DNA becomes a non-issue (for the purposes of identifying the defendent) for the defence the instant it doesn't match the defendent (in general)

That's quite a conclusion to draw from this story. Unless I'm missing something there is no suggestion that Mr Butler was framed, and the jury found him innocent.

The article is far more nuanced - it raises questions over the manner in which forensic work has been privatised and split up, leading to a situation where untrained officers are required to determine what forensic evidence to look for and what tests to perform. That's a worrisome prospect but I can't see in it the slightest suggestion of your scen

Slashdot had an article years ago about how people match within the DNA data base when you point it at itself for matches. Most notably was a black man and a white man that match. Someone pull that article up.

That's a result of the birthday paradox. In a one person to one person comparison, the chance of having the same birthdate is 1 in 365. If you compare each of 23 people to each of the others, the chance of matching the birthdates is 1 in 2 and the chance rises to 99% at 57 individuals (see birthday problem wiki). The same issue means that even with arbitrarily low rates of false positives, if your database is large enough, the chances of samples from two different individuals matching improve drastically

Virtually all of them aspire to high political office, thus they are hard-core 'Law and Order' a-holes and more than willing to ingore or suppress evidence or scene DNA contamination.

Look at their behaviour when DNA is not on their side; older cases where no DNA of the suspect is found. They always say the same thing: no, we got the right man; he was just more careful than his 'unindicted co-conspiritor'...

It's worth bearing in mind that this case is from the UK, where the case is directed by the Crown Prosecution Service using evidence gathered by the Police. There is no equivalent to a District Attorney.

1) It is much harder to move a fingerprint to frame someone. Yes, you could unscrew a light switch from your framing target, and trade it with the dead guys, but that can be detected fairly easy. You can on the other hand, grab a hairbrush from a framing victim and remove some hairs and leave it at the dead guy's body. Not to mention that it is incredibly easy to copy DNA - that's what makes it the stuff of light..

Except that no one has actually done the population level research needed in order to prove that fingerprints are unique, and two different finger print analysts are very likely to come up with different analyses of the same print.

There has not been a known case of two people having the same fingerprint

Which is irrelevant if different fingerprint analysts cannot reliably score the same fingerprints the same way.

"Anything you say can and will be used against you in a court of law."

These are not magic words. It is a statement of fact. The emphasis I've added is what is important to you (IANAL, but nobody needs to be to understand the basics).
There are only a couple, very easy to remember, things that should come out of your mouth when talking to law enforcement of any kind if you want to avoid being detained for 8 months for something you didn't do:

1. Name, Date of Birth, address of residence.

2. Am I being detained / Am I free to go?

3. I cannot speak to you without my lawyer present.

That. Is. It.

Don't be a jerk to cops, but do not offer information. Even if they ask nicely.

That's the US though, the UK has a different statement of fact: "it may harm your defence if you fail to mention when questioned something you later rely on in court"

You're too far down the legal road. These 3 points apply equally well in the UK as they do in the US for the point in legal proceedings that I'm talking about: Your first encounter with law enforcement.

The UK rules are simply setup to encompass more forms of communication (namely, being quiet) than just verbal. Imagine a kid swirling the dirt with his toes rather than verbally saying "yes, I did" when asked "Did you take a cookie from the jar?" In the UK, they'll look at both as admission, the verbal on

Interesting to note that both DNA and CCTV evidence were unreliable in this case. If neither of those two are reliable, and they can both be wrong in the same case, and I suspect that most would agree that these should be expected to be more reliable than eye-witness and circumstantial evidence, one has to ask some profound questions about the modern systems of criminal justice.

One thing that's horribly misleading is when prosecutors say "the likelihood of this match occurring at random is one in a quadrillion" or similar. If there aren't a quadrillion people on the planet, that statement means nothing. Also it's based on a lot of independence assumptions that may or not pan out. The irony is that the answer is out there - with all of the DNA database information that's been compiled by different law enforcement agencies, there is the ability to actually go and test to see whet

No, it is not. The current testing/matching methods put the chance of a duplicate at (I believe) 1 in 1000 - that's a whole lot of duplicates if you have a country or state-wide database. DNA is amazing tool in identifying a single person out of a small amount of suspects with the means and motive to commit the crime, say 1 out of 10 or 20. The probability of finding a duplicate in that small sample-pool is very small. This is why any attempt at building a comprehensive DNA database should be fought vigorou

I worked on code for a forensic DNA device. The FBI selected and standardized the DNA segments to be examined a long time ago, when it was harder to do and they didn't think they would be comparing millions of samples. Even though we could have made the device's test more accurate, it would not have violated standards and we wouldn't have been able to sell it for forensic purposes. At the time there were about two million people in their database, and you would expect several hundred matches per test.Anothe

"The police are getting lazy" is a gross understatement. When they "compare" DNA samples, they don't sequence each sample and do a complete match on the resulting sequences. Rather they do a crude comparison with techniques like gel electrophoresis and say "we think they match". While such a test might be good enough to rule out a non-match, it would be like saying "the shadow of the suspect (or at least a shadow we saw somewhere nearby) looks something like yours, so we are declaring you guilty".

When I was on grand jury duty, we had a few cases involving DNA evidence. Each time, the crime lab tech would repeat the same well-rehearsed statement that the odds against finding a match by chance would require something like "100 trillion earths with a population of 10 billion individuals" to find someone with a particular DNA sequence.

I regret not using my prerogative as a grand juror to ask them if the chances of contamination or a lab error were less than that number.

Again, let's suppose that there are 1 million possible DNA profiles (they are not a complete sequence remember). So 2 random samples would have about a 1 in one trillion (with a T) chance of matching. However, if you take a single sample and compare it to a database of 10 million samples you will almost certainly get a match - probably more than one.

Let's face it, our educational standards have dropped to such a low point that most juries in America can be swayed by any motivated and well funded prosecutor. There's enough DNA evidence to convince the average jury that I am in fact a Chimpanzee, just by showing them that I share 96% of chimp DNA. Prosecutors are quick to point out the difference between "shadow of a doubt" and "reasonable doubt" - 96% DNA clearly removes any 'reasonable' doubt that I am not a chimp. People have been executed in this country within the last decade with even flimsier evidence.

Most murder suspects have to pay their life's savings and rack up additional years of debt to cover legal expenses while simultaneously losing earning opportunities, usually resulting in bankruptcy even if they are acquitted. Even when they hire an attorney they usually don't have the funds to put up an equivalent defense compared to state budgets. The cost of legal defense can devastate an entire extended family. When Brian Banks was falsely accused of rape his mother sold her house, car and went into debt to cover his legal expenses. He is an NFL hopeful with a goal to make enough money to pay back his mother. Not every falsely accused will have such an opportunity.

Having a public defender appointed to represent you just means you get an under-paid, unmotivated lawyer that just wants to wrap up the case quickly with an admission of guilt or a plea agreement. But the state can spend $10 million on just one case in the name of being "tough on crime". Prosecutors have to win almost every case that goes to trial or force the accused to accept archaic plea deals. If they let suspects walk on lack of evidence it becomes front page news, and it damages their future prospects, especially if they seek election to a public office. The emergence of the Prison-Industrial Complex is one of the greatest present-day threats to our democracy and individual freedoms. Pray it doesn't happen to you.

There was a guy here in Sweden who is in jail for rape. He recently got convicted for the further crime of smuggling sperm out with his son who was then supposed to rape a woman, leave the sperm sample there, and thus throw some doubt into the validity of the conviction of his father.

(In a finger cut off a latex glove, if I recall correctly, since I know you're all very curious.)

The problem with cases like this is that they make things like that possible. If DNA is all you need, then it doesn't really take much... a few shakes, scratch your head... hell, they grab DNA off the saliva on cigarette butts. With the advances in the technology, soon enough you'll cough on the bus and a week later get arrested for the crimes committed by some guy who sat down in the same seat 20 minutes later.

There's really only one thing we need to solve this, and amusingly it is also needed to solve another major issue with the legal system... We need a legal system, and specifically judges, that are familiar with both technology and science. Well familiar. I mean, you could even argue that the judge should BE a scientist... setting up a null hypothesis before the trial, and doing careful testing to either validate or disprove the hypothesis.

Maybe that would cut down on the amount of "patent suits" judged on by people who have no idea what a mouse pointer is.

The problem isn't DNA per se, it's police jumping at the first hint of a connection and assUme-ing causality where none is actually suggested. OK fine, you found joe-schmoe's DNA on someone. That means at MOST that Joe Schmoe was in contact with the victim at some point in fairly recent history. Perhaps he bumped in to him on the sidewalk going to lunch. It could mean a lot less, for example they both checked their coats at the same restaurant at lunch and never saw each other at all. All of that and it remains entirely possible that Joe is telling the truth when he claims to not remember the victim at all. In the latter case, he COULDN'T remember him.

It is one more clue amongst many that might lead to a criminal, but that's it. It is not some sort of end all and be all.

So you found Joe's DNA on the hammer that killed the victim. You now know that either Joe touched the hammer in the last few days OR that someone who was in contact with Joe touched the hammer in the last few days. That's hardly damning, you'll need a lot more to put the hammer in Joe's hand as it struck the victim's head.

All of that is before we even consider chance matches, cross-contamination, or lab error.

Conclusion: Prosecutors will really want to strike me from the jury. They don't want to deal with actually proving the case, they just want to put someone (anyone) in jail.

Brings to mind the Leskie DNA incident [theage.com.au]. The funny thing was that for months after the rape victim's DNA had been found on the murdered child's clothing, police and forensic investigators flatly denied that it could have been caused by contamination.

Which is exactly why I never donate used clothing or shoes to Goodwill. So what if they wash them? Prove to me that no DNA survives the washing process. DNA survives a lot of stuff- giving rise to certain techniques in paleo-anthropology. In fact , that wash probably only hurts your chances at a defense, the same way having your password hacked on your wireless hurts you more in your illegal download defense than if you had left your WIFI open to anyone.